COLORADO SPRINGS, Colo. The debates over distributed and centralized core routers that attended Cisco Systems Inc.'s May launch of the CRS-1 router have been revived by Cisco's close competitor, Juniper Networks Inc.
Juniper (Sunnyvale, Calif.) is launching its TX Matrix switching platform, which will use fiber arrays linked via Clos-architecture switches to combine up to four T640 routers.
The resulting TX Matrix cluster will be able to forward up to 3 billion Internet Protocol packets per second, all in a single logical router domain.
The T640 was designed with interfaces to a switching matrix in mind, said Todd Shimitzu, director of product marketing for Juniper core routers. While Juniper would consider any means of scaling routers in the future, the company has singled out the high-end T640 as its platform for the switched router cluster. Neither the T320 nor the M and E series routers at Juniper will be linked in a cluster like the T640.
To develop the TX Matrix, Juniper used the 19-inch chassis of the T640, but populated it with slots for up to five fabric modules. Each switching-fabric card uses VCSEL arrays of lasers for a fiber interconnect operating from 10 feet to 110 yards. The TX Matrix still uses control-plane route engines to control switched IP traffic, but the fiber connections are on the front panel of the TX system, while the control processors are in the rear of the chassis. Conversely, the fiber interfaces for the T640 routers are in the routers' rear panel.
The switching platform implements a three-stage Clos network, which Juniper called the most efficient switching topology. Matt Kolon, senior technical marketing manager at Juniper, said the Junos operating system views the cluster as a single logical entity, and it was important to network planners and customers alike that the linked routers could scale to new performance levels while using the same operating system as all single-chassis routers. By contrast, Cisco is moving to a new version of its IOS with the CRS-1 router.
"The problems with a major change in operating system could end up being greater than the problems of a new hardware platform," Kolon said.
Cisco has tried distributed cluster operations with earlier 12000 platforms, but Juniper will be blazing new trails with successful distributed terabit operations if its TX Matrix architecture catches on with additional customers.
Tom Nolle, president of market analysis firm CIMI Corp. (Voorhees, N.J.), said Cisco is said to be working on a smaller version of CRS-1 to better fill the gap between the GSR and CRS series of routers. But "Cisco's traditional focus on the Internet service provider," he said, "has caused the company to view its routers as very atomistic standalone products, making scaled interconnect a bigger problem." Juniper's "radical step," Nolle said, was in realizing that common carriers were determining router architectures more than ISPs.
"The common carrier is now driving the router market, and the Internet concept of system architecture is an inconsequential issue," Nolle said. "That common carrier already believes the deep core is going to be optical, so there's really no need for a 10- or 40-terabit router in a single system."
Nolle said that fiber links extending to 110 yards were interesting when the distributed hardware can be viewed as a virtual router, with a single logical-node image. The bankrupt Allegro Networks Inc. was the only company to announce that it was working on virtual router software. But Nolle said Juniper had quietly added such capability to the Junos software two years ago. The 110-yard fiber distance with TX Matrix will be interesting for helping carriers with central-office space constraints, Nolle said, "but the real revolution will come when we can extend virtual router images across metropolitan distances, making a single distributed router span a metro region."